libbb: allow dumping of /dev/fd file descriptors

xxd and hexdump use library code to dump binary data.  This code
uses freopen(3) which can't handle /dev/fd file descriptors.  Rewrite
it using fopen(3).

1 files changed, 36 insertions, 0 deletions

diff --git a/libbb/dump.c b/libbb/dump.c
index fb7849e7d..196ccfe65 100644
--- a/libbb/dump.c
+++ b/libbb/dump.c
@@ -37,6 +37,9 @@ typedef struct priv_dumper_t {
         off_t address;           /* address/offset in stream */
         int blocksize;
         smallint exitval;        /* final exit value */
+#if ENABLE_PLATFORM_MINGW32
+        FILE *fd;
+#endif
 
         /* former statics */
         smallint next__done;
@@ -58,6 +61,9 @@ dumper_t* FAST_FUNC alloc_dumper(void)
         dumper->pub.dump_length = -1;
         dumper->pub.dump_vflag = FIRST;
         dumper->get__ateof = 1;
+#if ENABLE_PLATFORM_MINGW32
+        dumper->fd = stdin;
+#endif
         return &dumper->pub;
 }
 
@@ -328,7 +334,11 @@ static void do_skip(priv_dumper_t *dumper, const char *fname)
 {
         struct stat sbuf;
 
+#if ENABLE_PLATFORM_MINGW32
+        xfstat(fileno(dumper->fd), &sbuf, fname);
+#else
         xfstat(STDIN_FILENO, &sbuf, fname);
+#endif
         if (S_ISREG(sbuf.st_mode)
          && dumper->pub.dump_skip >= sbuf.st_size
         ) {
@@ -337,7 +347,11 @@ static void do_skip(priv_dumper_t *dumper, const char *fname)
                 dumper->address += sbuf.st_size;
                 return;
         }
+#if ENABLE_PLATFORM_MINGW32
+        if (fseeko(dumper->fd, dumper->pub.dump_skip, SEEK_SET)) {
+#else
         if (fseeko(stdin, dumper->pub.dump_skip, SEEK_SET)) {
+#endif
                 bb_simple_perror_msg_and_die(fname);
         }
         dumper->address += dumper->pub.dump_skip;
@@ -353,12 +367,22 @@ static NOINLINE int next(priv_dumper_t *dumper)
                 if (fname) {
                         dumper->argv++;
                         if (NOT_LONE_DASH(fname)) {
+#if ENABLE_PLATFORM_MINGW32
+                                dumper->fd = fopen(fname, "r");
+                                if (!dumper->fd) {
+#else
                                 if (!freopen(fname, "r", stdin)) {
+#endif
                                         bb_simple_perror_msg(fname);
                                         dumper->exitval = 1;
                                         continue;
                                 }
                         }
+#if ENABLE_PLATFORM_MINGW32
+                        else {
+                                dumper->fd = stdin;
+                        }
+#endif
                 } else {
                         if (dumper->next__done)
                                 return 0; /* no next file */
@@ -413,13 +437,25 @@ static unsigned char *get(priv_dumper_t *dumper)
                         dumper->eaddress = dumper->address + nread;
                         return dumper->get__curp;
                 }
+#if ENABLE_PLATFORM_MINGW32
+                n = fread(dumper->get__curp + nread, sizeof(unsigned char),
+                                dumper->pub.dump_length == -1 ? need : MIN(dumper->pub.dump_length, need), dumper->fd);
+#else
                 n = fread(dumper->get__curp + nread, sizeof(unsigned char),
                                 dumper->pub.dump_length == -1 ? need : MIN(dumper->pub.dump_length, need), stdin);
+#endif
                 if (n == 0) {
+#if ENABLE_PLATFORM_MINGW32
+                        if (ferror(dumper->fd)) {
+#else
                         if (ferror(stdin)) {
+#endif
                                 bb_simple_perror_msg(dumper->argv[-1]);
                         }
                         dumper->get__ateof = 1;
+#if ENABLE_PLATFORM_MINGW32
+                        fclose(dumper->fd);
+#endif
                         continue;
                 }
                 dumper->get__ateof = 0;